


professor river song, defense against the dark arts

by justjoy



Category: Doctor Who (2005), Harry Potter - J. K. Rowling
Genre: Alternate Universe - Canon Divergence, Crossover, Gen, Inspired By Tumblr
Language: English
Status: Completed
Published: 2013-09-02
Updated: 2013-09-02
Packaged: 2017-12-25 10:02:42
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,542
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/951787
Author URL: https://archiveofourown.org/users/justjoy/pseuds/justjoy
Summary: <blockquote class="userstuff">
              <p>Inspired by <a href="http://presumenothing.tumblr.com/post/60076044942/killerladyboner-addictedtoemma">this gifset</a> on Tumblr - River Song as the new Defense Against the Dark Arts Professor.</p>
            </blockquote>





	professor river song, defense against the dark arts

**Author's Note:**

> I... literally don't know what happened, and then suddenly this fic appeared. Yes. That's all I'm saying.
> 
> Sixth year.

The door to the Room of Requirement materialised on their third run past, and they rushed in just as Peeves' mad cackling intensified, although the poltergeist was nowhere to be seen.

Harry was still checking the corridor when he registered a small shriek behind him, right before Hermione's hand darted out past him to grab the doorway very firmly.

"Hermione? What - "

Then Harry turned around, and nearly stumbled as well - because there was magic, and there was Hogwarts, definitely, but this was something _else_.

Outside the skewed rectangle of light that spilled in from the seventh floor corridor, everything else fell away into shadow, darkness that would have been unrelenting if not for the brilliant bursts of light everywhere he looked, complex swirling shapes scattered among dimmer pinpricks.

And far away, though the true distance was hard to judge, a blue box drifting unanchored in the vast space, off-white light shining from the windows set into its two doors - one of which now swung open slowly.

Before Harry could reach for his wand, though, a familiar voice floating to them through the echoing silence. "Oh, hello. I wasn't expecting you. Was I?"

" _Luna?_ What're you doing here?" Ron sounded as surprised as Harry himself was. 

"Why not?" Luna answered in her usual vague manner. "Come on, you're letting the Nargles in."

"Wait," Harry muttered, putting out a hand to stop Ron before he could step forward. 

"Prove it," he said loudly, surreptitiously palming his wand so that it was still concealed by his sleeve. He hated having to do this - the words certainly  _sounded_  like Luna's, but they had to be sure. "Prove you're her."

Luna didn't even look fazed by the request; she merely raised her wand, a wisp of silvery light already issuing from the end. It coalesced into the unmistakeable form of a hare, which bounded over and sniffed at Hermione's hand before dissipating.

Ron snorted and set off at a brisk trot towards the box, leaving Harry and Hermione to stare wide-eyed at the fact that he was actually managing to walk at all.

Carefully, Harry prodded the area in front of them with a foot, and was rewarded with a relatively solid surface for what appeared for all intents and purposes to be an empty void.

"We're in space. In  _Hogwarts_ ," he heard Hermione mutter in disbelief as she strode past him, and couldn't help his wide grin in response as he followed.

This wasn't even anything like the photographs of space he'd seen in one of the  _National Geographic_ magazines back in the Surrey Public Library, let alone the crappy illustrations in Dudley's old textbooks. 

This was _awesome_.

* * *

 

Harry closed the door of the box behind him just in time for the rare sight of Hermione Jean Granger, completely and utterly _bewildered_.

" _Professor Song?_ But - _how?_ We didn't even find this room until last year! The Professors don't know about it - Headmaster Dumbledore only stumbled upon it _once_ , by _accident_!"

And indeed, there was their newest Defense Professor sitting in what seemed to be a control room of some sort, a blue book propped open on her lap.

"Um, Hermione?" Ron sounded bewildered as well, but for clearly different reasons. "Couldn't Luna have told her about it? I mean, we used this place for DA meetings all the time last year, everyone knows where to find it."

"But not _how_!" snapped Hermione. "And that's not the only strange thing. What we saw out there was space, _actual_ space, I've never even seen any footage that _detailed_ , and last I checked _wizards haven't invented space travel_! Information like that can't just appear out of nowhere if you don't already know it or have access to it, all the books that appeared when we asked for them last year during DA were already written beforehand - knowledge is the fourth of the five Principal Exceptions to Gamp’s Law of Elemental Transfiguration, even the Room of Requirement can't possibly create space at anyone's request if they _don't already know what it looks like._ Not to mention, this is a police box from the _1960s_ , a _Muggle_ police box to be exact, and - none of this makes any _sense_!"

Harry wasn't sure if Hermione had merely run out of breath by this point or was genuinely speechless.

From what he could see, though, the Defense Professor's smile was almost definitely approving, which probably meant that she'd understood everything Hermione had just said.

That was a remarkable achievement in itself, actually, since the only other person who'd proven consistently capable of keeping up with Hermione in that mode was Professor McGonagall. Some of the Ravenclaws came close every now and then, albeit with heavy use of DictaQuills and their seemingly bottomless book bags. (Luna, being Luna, occasionally managed to do it without seeming to have paid any attention at all, which was a mystery that probably even Hermione wouldn't be to explain, not that he'd tried asking.)

 _Well, at least that makes one of us,_ Harry thought somewhat dazedly, having lost Hermione's train of thought somewhere along her third sentence.

Beside him, Ron had taken to directing confused looks between Hermione and Professor Song, who had set her book aside and was now tapping away at something black strapped to her wrist like a watch -

\- _vanished_ without even the slightest sound to hint at Apparition - 

\- and Harry turned around on pure instinct bare fractions of a second before Hermione did, although it didn't stop either of them from starting in surprise when the Professor materialised right between them and the door.

"Correct on every point, Miss Granger! Except - no, of course, _spoilers,_ " she added, green eyes alight with amusement. "And I must add that you could have done better on your closing remarks."

Harry had just managed to conclude that this Professor was quite possibly the most eccentric one they'd had yet - and why was she so fond of that particular word anyway? - before they found themselves being herded towards the console, where Luna was just setting down a tray with several mugs.

The Ravenclaw giggled when she caught his wary sniff at the contents of the mug she handed to him. "It's perfectly safe, Harry. I checked, there aren't any Vanishing Nymphpoles in the water, although I'd love the recipe if you don't mind, Professor. The house elves agreed to share the ingredients for their brownies if I brought some new recipes. I'll make sure Dad doesn't publish it accidentally, there's no telling what the Heliopaths would do if they got their hands on it," she finished with a completely serious expression.

"I certainly wouldn't mind at all, Miss Lovegood, although some of the ingredients might be hard to obtain here on Earth. Remind me to introduce you to one of my friends, she loves making souffles. And I can assure you that this is quite safe for consumption, Mr Potter, unless you're allergic to anything from the planet Clom."

Harry grinned sheepishly when he realised that he hadn't even taken a sip of his drink, although he'd been distracted at least in part by the many levers and buttons visible on the console. He took a tentative mouthful and was pleasantly surprised at the taste, although it was indeed like nothing he'd ever tried before. (Which, he noted, was actually quite solid evidence that the Professor had indeed been serious about getting ingredients from... somewhere very much  _not_ Earth.)

"Sorry. We don't exactly have the best track record with Defense Professors around here."

Professor Song shook her head, the amusement from earlier still obvious in her smile. "I've heard as much. Don't worry about it, I know quite a bit about paranoia myself. Now, I'm aware that you lot use this room quite often, as I plan to do myself, so I imagine that we might be seeing quite a bit of each other this year. This is the TARDIS, you're welcome to come and go as you wish, although it might be a good idea to do a Point Me spell to this control room every now and then if you decide to wander around. She's an old friend, but she does get slightly temperamental every now and then."

"But wouldn't we be intruding, Professor?" Hermione's brows were knitted with faint concern tinged with the familiar curiousity. "I mean, it's all right if you want to use the Room, we can just find somewhere else to go."

"Nonsense, there's more than enough room for everyone," the Professor answered airily as she stood and collected their mugs.

Which was quite true, as far as Harry could see - the corridors that led outwards from the control room seemed endless. Strangely enough, though, Professor Song seemed to be heading towards a _different_  corridor from the one where Luna had originally brought the mugs from.

"And do correct me if I'm mistaken, Miss Granger," added the Professor with a wink at Hermione right before disappearing into the corridor, her voice still carrying clearly over to them somehow, "but I don't believe you'll still be saying that once you've seen the library."

Hermione's badly disguised squeak of surprise almost covered Ron's muttered  _she'll say yes to anyone who gives her a library_.

Well, _almost_.

**Author's Note:**

> This plot bunny goes on to add that River's reasons for coming to Hogwarts, besides being a completely awesome mentor to everyone as described above, is also because she needs Hermione's help (because, y'know, brightest witch of her generation and all) in reversing Oswin's Dalek-fication, which is just a very extreme form of transfiguration depending on how you look at it. This follows headcanon from my other [DW fic](http://archiveofourown.org/works/704166) that River rescued Oswin from the Asylum right before it exploded.
> 
> Also, this is very much unedited, and I'm really out of touch with HP so apologies if there's any glaring errors that I haven't spotted.


End file.
